Sales of periodical literature are becoming increasingly popular. Subscription providers publish new issues on a regular basis, such as daily, weekly, monthly or quarterly. The most familiar examples are newspapers or magazines. The periodicals are typically referenced by volume and issue numbers. The volume refers to the number of years that the publication has circulated, while the issue refers to how many times the periodical has been published during any given year. More recently, publishers are allowing issues to be accessed digitally over the Internet.
The New York Times is an example of a newspaper that allows active print subscribers access to digital issues of the newspaper. For example, a print subscriber to the New York Times receives an automatic free all-digital subscription, which allows access to content using smartphones, tablets, and computers. For digital access, an application is downloaded to the user's client device. The user then clicks on the application and the application calls a dedicated New York Times server. After an authentication process is completed, the user obtains access to the desired digital issues. If the user terminates their print subscription, then all digital access rights are terminated. Digital only access is also available.
In order to allow access to digital issues, the New York Times invested in server and software development at a high cost. Other companies that want to publish periodicals must individually duplicate the efforts of the New York Times. Thus, each publisher must develop all of the software and systems needed to authenticate users and format the content for particular clients.